Interdecadal changes in the interannual variations in spring precipitation over the Tarim Basin

Abstract

AbstractThe year‐to‐year fluctuation and total amount of spring precipitation over the Tarim Basin (TB) (SPTB) have both significantly increased after 1985. The data are then divided into two subperiods, that is, 1961–1985 (P1) and 1986–2020 (P2), and the contributions from various climate factors, including the North Atlantic and Indian Ocean sea surface temperatures (SSTs), as well as from Tibetan Plateau (TP) snow, to the interdecadal changes from P1 to P2 are examined. In P1, the SPTB‐related atmospheric circulation anomalies display a zonal wave‐like pattern dominating the middle–high North Atlantic‐Eurasian continent. In contrast, in P2, the SPTB‐related atmospheric circulation anomalies feature a meridional tripole pattern prevailing over the North Atlantic and western Europe. The observational analysis indicates that abnormally low pressure in the north and high pressure in the southwest of the TB are the key atmospheric systems that influence moisture transportation to the Tarim Basin and consequently impact the variability of the SPTB. The anomalous SSTs in the North Atlantic and Indian Ocean play a significant role in inducing changes in the SPTB by regulating the moisture transport pathway in the vicinity of the TB. In P1, the SSTs in both the North Atlantic and the tropical Indian Ocean contribute to the SPTB mainly in the periphery of the TB, while in P2, they contribute to the SPTB in most of the TB. In addition, the snow cover over TP also contributes to the SPTB changes. Distinguished from the effects of oceanic SST, the TP snow primarily influences the variability of the SPTB within the central region of the TP during P1 and around the periphery of the TP during P2.